An unanswered call at four in the afternoon is a lost tour
The largest single conversion loss in most brokerages is not on the website at all; it is the phone.
Commercial inquiries still arrive by phone and the caller is often mid requirement with a shortlist. If it rings out, they call the next firm on the page.
Start by counting. Pull three months of call records and look at answer rate by hour and by day, missed calls with no callback within an hour, and calls that reached voicemail during business hours. Almost every firm is surprised by this number.
Then fix coverage rather than technology. A named person responsible for the main line each afternoon, an overflow to a mobile, and a rule that every missed call gets a callback the same day.
Only after that is call tracking worth installing, because tracking a broken process just produces a better documented loss.